Telling our left from our right isn’t as easy as we’re supposed to believe. Studies reaching back to the 1970s have consistently found that a large chunk, perhaps a fifth of the population, have trouble determining which side is which. And more women than men have difficulties.

The picture, says JSTOR’s Diane Peters, is grim. Kids start out having no idea about left or right, adults aren’t nearly as good at it as we might assume, and if you get sick, or when you get older, the skill wanes again.

"One study of 148 children," says Peters, "found only 70% of five-year-olds got seven questions regarding left and right on their own bodies correct." A 1973 study of 382 women and 408 men concluded that "Right-left confusion occurs often in adults, even of superior intellect, and is statistically commoner in women."

A surgeon may operate on, or even amputate, the wrong leg.

Drug addicts lose some ability to discriminate left and right, as do sufferers of certain brain injuries.

The most obvious result of this inability is following directions. Co.Exist editor Morgan Clendaniel says that he can’t tell left from right at all. When he’s driving and people say "turn left," he says that nothing happens his brain, which may be why so few people ever ask him for a ride. But the consequences can be a lot more drastic. A surgeon may operate on, or even amputate, the wrong leg, for example, something common enough that in some hospitals, a doctor will mark up a patient's leg with a sharpie while the patient is still awake.

But why is it so hard to tell left from right for so many people?

The fact is that telling left from right isn’t that important. In fact, some cultures can give directions without referring to left or right—called relative, or "egocentric" coordinates. Instead, they use absolute, or geographic, directions like north and south.

Using context, simple directions can indicate absolute destinations.

The Guugu Yimithirr, from north Queensland, Australia, don't use any egocentric directions. In a 1997 paper, researcher Stephen Levinson showed that "Guugu Yimithirr is a language more or less completely absolute in spatial description." Instead, it divides the world into four "edges," or quadrants, and people can talk about going to or from one of these quadrants, or being within one of them. Using context, simple directions can indicate absolute destinations. "‘I am going north' may already be sufficient to unequivocally specify that I am going, for example, to the beach," writes Levinson.

The system works fine, although from our point of view some of its characteristics may seem confusing. For instance, you must have a frame of reference to understand directions, or any story involving movement or space. The language is also full of gestures, which help give this context, and its speakers have a much more acute sense of north and south than most. The system has clear advantages: If you ever arrived in a city by train, and then tried to follow directions starting "take the left exit and turn right," then you’ll appreciate a system that could never be so confusing.

One other oddity in Guugu Yimithirr is that you don’t have a left or a right hand. You can have an eastern hand, which becomes a western hand when you turn to face the other way. In this manner, the language works like port and starboard, a successful workaround for left-right confusion on boats.

Which is to say, you should’t feel too bad about your dismal skills. Not only are you in a rather large minority, but some cultures manage without left or right altogether. You don’t need to learn move to Australia and learn Guugu Yimithirr, either. Just take solace in the fact the even the majestic Richard Feynman had trouble telling left from right. "In his entire life he could never quite teach himself to feel a difference between right and left," writes Brain Pickings’ Maria Popova, "but his mother finally pointed out a mole on the back of his left hand, and even as an adult he checked the mole when he wanted to be sure."

And speaking of Feynman, here he is using absolute directions to clear up a confusion about how mirrors work, because we usually describe their reflections, and their apparent left-right reversal, with egocentric directions:

And remember, if you’re a surgeon or a dentist, make sure to double check before you lop off anything important.

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